That's usually how people die in horror movies. Do you know anyone who can fly? Maybe an aerial overview would help and could work for navigating a group. And if it's not in there, it saves everyone from getting lost.
Less evidence is always good when trying to kill someone discretely. I can't become intangible, but I think we might have abilities on a similar spectrum. I can't phase someone into a wall, though. But I understand that when you hold something or you wear something it becomes a part of you and you can move with it bit.